Arjowiggins Graphic in conjunction with HP has initiated a second extended industrial trial at its Greenfied de-inking plant using waste paper containing 5% of HP Indigo printed paper.

The relationship with HP is aimed at improving the ability to de-ink printed materials from HP Indigo and HP inkjet digital presses. This will ensure that paper from HP Indigo Liquid Electrophotographic (LEP) and inkjet digital print jobs can be recycled and ultimately avoid landfills.

While currently the amount of LEP and inkjet materials found in the recycling process is small relative to analogue prints such as offset lithography, the use of these types of digital printing technologies will increase. It is therefore essential for the industry to develop effective solutions to ensure compatibility with recycling mills, such as those operated by Arjowiggins Graphic, when digital prints become a more significant portion of the recovered paper stream. The results from the latest trial confirm that a minimum of 5% HP Indigo print in the waste stream can be used without detriment to yield or quality of the de-inked pulp. Andrew Findlay, Arjowiggins Graphic R&D Director, said: "This confirmation of the first trial, in conjunction with laboratory protocols in the process of being developed by HP, provides a solid base line for the future optimisation of de-inking chemistry or the exploration of increased levels of Indigo printed paper in the waste supply."